As one of the most prevalent gastrointestinal malignancies in humans, gastric cancer (GC) is often detected at an advanced stage, resulting in a poor prognosis and ranking it the fifth leading cause of cancer-related deaths. Due to their high genomic correlation with humans, mice are ideal in vivo models for investigating GC-related pathogenesis and therapeutic interventions. This review provides an overview of different GC models, including genetically engineered, transplantation-based models, and chemically or biologically induced models, and discusses the recent advancements for each type, highlighting their unique contributions to the field. In addition, it summarizes the strengths, limitations, and typical applications of these models and offers a critical assessment of their applicability in research while acknowledging their current limitations in fully mirroring human GC progression. Furthermore, we analyze how each model accurately recapitulates the complexities of human GC and evaluate their potential for clinical translation. This review provides a reference for model selection in future GC research.

Vitamin D, with its diverse molecular pathways and immunomodulatory properties, has become a crucial tool in the prevention and treatment of various cancers. It controls angiogenesis, apoptosis, differentiation, and cellular proliferation, inhibiting cancer through immune surveillance, DNA repair, and tumor suppression genes. Additionally, vitamin D signaling impacts tumor growth and metastasis in various cancer types by interacting with key oncogenic pathways like Wnt/β-catenin, NF-κB, PI3K/Akt, and p53. This review demonstrates the molecular and therapeutic implications of vitamin D in oncology, focusing on its potential as a safe, adjuvant treatment method. It emphasizes the role of vitamin D in epigenetic modification, its impact on tumor microenvironment, and its synergistic benefits when combined with immune checkpoint inhibitors and chemotherapeutic drugs. Despite promising results, genetic variations in the VDR gene continue to cause issues with bioavailability, ideal dosage, and interindividual response variability. The review also proposes future research on vitamin D's potentiality as a therapeutic adjuvant in various malignancies, including colorectal, prostate, and breast cancers, and suggests the development of non-calcemic vitamin D analogs and the incorporation of vitamin D-based methods into personalized oncology treatments.

Background: Allergic rhinitis (AR) is a kind of immune disease mediated by IgE. We are intrigued by the potential role of DEK proto-oncogene (DEK) in inflammation-related diseases. We investigated the effects and mechanisms of DEK in treating AR, aiming to identify potential new treatment targets for AR.

Methods: The AR mouse model was induced by house dust mite (HDM) (1 mg/mL). HNEpCs stimulated by HDM (1 mg/mL) were pretreated for 24 h with or without DEK lentivirus. The effect of DEK knockout or knockdown on AR was evaluated in vitro and in vivo using western blotting, ELISA, flow cytometry, real-time quantitative PCR, immunohistochemistry, HE staining, PAS staining, Diff staining, and immunofluorescence.

Results: After DEK knockdown, the inflammatory response of AR mice was reduced. In addition, DEK deletion mitigated nasal tissue damage and mitochondrial division. Our further studies showed that DEK deletion or inhibition led to the down-regulation of RhoA activity and decreased phosphorylation of Ezrin and Drp1 proteins, and inhibited mitochondrial division. Overall, DEK deficiency mitigated AR by down-regulating RhoA/Ezrin/Drp1 pathway activity.

Conclusion: DEK alleviates AR through RhoA/Ezrin/Drp1 signaling pathway, which provides a new perspective for developing improved therapies and understanding the pathogenesis of AR.

Background: Cancer-associated cardiac cachexia (CACC) refers to cardiac injury in cancer patients in a malignant state, but preclinical animal models remain inadequately developed.

Methods: This study established CACC models in C57BL/6J and BALB/c mice using orthotopic, intra-abdominal, and hematogenous metastatic tumor induction. Multimodal cardiac assessments, including echocardiography, transmission electron microscopy for myocardial ultrastructural and mitochondrial analysis, and ex vivo cardiomyocyte contractility assays, were systematically applied.

Results: Metastatic burden triggered CACC characterized by cardiac mass reduction, epicardial fat depletion, interstitial fibrosis, and electrocardiographic abnormalities. Histopathological analysis revealed cardiomyocyte atrophy, myofibrillar disarray, mitochondrial dysfunction, and ubiquitin-mediated Myh6 degradation via MuRF-1, accompanied by compensatory Myh7 upregulation. These findings mechanistically link tumor-induced cachexia to cardiac dysfunction through contractile protein remodeling.

Conclusion: This work establishes a preclinical framework for targeting ubiquitin pathways to mitigate the morbidity of cancer-related cardiopathy. Our integrated approach delineates a hierarchical progression from subcellular dysfunction to macroscopic cardiac deterioration.

Background: Constitutional mismatch repair deficiency (CMMRD) is a rare disorder resulting from biallelic germline pathogenic variants in mismatch repair genes. This study described the molecular profile of two metachronous brain tumors and a patient-derived xenograft (PDX) from a Brazilian child with CMMRD.

Methods: After PDX development, methylation array, whole exome sequencing, and NanoString techniques were applied to describe the genetic landscape of CMMRD.

Results: A 6½-year-old girl was diagnosed with Sonic Hedgehog (SHH)-activated medulloblastoma and somatic TP53-mutant. After surgery and radiochemotherapy, she remained free of disease progression. At 10 years and 3 months, she developed a diffuse pediatric-type high-grade glioma (dpHGG). The child had a family history of cancer, and subsequent investigation revealed a biallelic germline variant on MSH6 (c.3556+1G>A) with the absence of protein expression in both normal and tumor tissue. A PDX model of the dpHGG was developed. The methylation profile confirmed the diagnosis of both brain tumors and PDX, refining the classification of dpHGG, Rtk1 subtype, subclass A, with an actionable alteration on Platelet-derived growth factor receptor A (PDGFRA). Exome analysis showed high tumor mutational burden, with 3019, 540, and 1049 pathogenic variants in the medulloblastoma, dpHGG, and PDX, respectively. Only the medulloblastoma exhibited microsatellite instability. The CD24, CD47, and CD276 immune checkpoints had elevated messenger RNA levels, yet no programmed death ligand 1 expression was observed in CMMRD-derived tumors.

Conclusion: We report an extensive molecular profile of a CMMRD patient, and the developed PDX model can be applied to explore new therapeutic approaches for CMMRD-associated brain tumors.

Background: The precise insertion of large DNA fragments (>3–5 kb) remains one of the key obstacles in establishment of genetically modified murine models.

Methods: A 21 kb large DNA fragment containing three tandemly linked copies of the human HRAS gene was inserted into the genome of C57BL/6J mouse, generating a mouse model designated as KI.C57-ras (or named NF-hHRAS). Whole-genome sequencing and Sanger sequencing were utilized to it confirm precise insertion and copy number. The stability of transgene expression among different generations was verified from multiple aspects using by digital PCR, western blot and DNA sequencing. To assess tumor susceptibility in the mouse model, N-Nitroso-N-methylurea (MNU) was administered at a dosage of 75 mg/kg. Histopathological examinations were conducted using hematoxylin and eosin (H&E) staining.

Results: The HRAS DNA fragment was inserted into mouse chromosome 15E1 site, locating between 80 623 202 bp and 80 625 020 bp. NF-hHRAS mice exhibited stable inheritance and displayed consistent phenotypes across individuals. Moreover, this mouse model exhibited a high susceptibility to carcinogens. Upon administration of MNU the earliest mortality onset was earlier than that of wild-type littermates (day 65 vs. day 78 for male and day 56 vs. day 84 for female). Notably, 100% of the NF-hHRAS transgenic mice developed tumors, with approximately 84% of male NF-hHRAS mice exhibiting specific tumor types, such as squamous cell carcinoma or squamous cell papilloma, which was consistent with the previously reported carcinogenic rasH2 mouse model. The types of tumors and the target organs exhibited diversity in NF-hHRAS mice, while the spontaneous tumor incidence remained low (1/50).

Conclusions: The NF-hHRAS mice demonstrated excellent genetic stability, a reproducible phenotype, and high susceptibility to carcinogens, indicating their potential utility in non-clinical safety evaluations of drugs as per the S1B guidelines issued by the ICH (The International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use).

Background: The Vietnamese swine represents a promising animal model due to its anatomical, physiological, and pathophysiological similarities to humans. Notably, the arrangement of lobes and ducts in the mammary glands is highly comparable to that of humans and is histologically indistinguishable. Leveraging these advantages through the chemical induction of carcinogenesis in this model offers a robust approach to mimic human exposure to carcinogenic compounds.

Methods: This study elaborates on a protocol for developing a representative model of MNU-induced invasive breast carcinoma in three Vietnamese swine, validated histologically and immunologically. It evaluates not only the tissue similarity with humans, but also the development of chemically induced mammary tumors in an immunologically competent animal. Moreover, this study addresses the existing gap in histological knowledge regarding mammary tissue in the porcine model.

Results: Our findings suggest that this model encompasses the full spectrum of cancer. It incorporates the key elements of a tumor microenvironment that enable tumor growth and propagation, such as immune cells, blood vessels, fibroblasts, extracellular matrix, fatty acids, and signaling molecules.

Conclusions: This model offers significant potential to advance the understanding of cancer pathogenesis and facilitate the development of innovative therapeutic strategies by closely replicating human tumor biology.

Radiological or nuclear accidents can lead to serious outcomes for individuals exposed to ionizing radiation, with health effects that are either acute or delayed, deterministic or stochastic, depending on the effective dose of exposure. Mechanistically, ionizing radiation can inflict damage either directly on DNA or through oxidative stress, which may trigger a cascade of damages to tissues and organs. The development of effective radiation medical countermeasures is an unmet need and should be a top priority in preparing for radiation emergencies. This paper aims to address the critical questions of whether current countermeasures are available, what additional measures are needed, and what actions can be taken to enhance the development of radiation medical countermeasures from a systematic perspective.

Robust preclinical models of transgender male (TGM) gender-affirming hormone therapy (GAHT) can inform clinicians of the isolated effects of GAHT; however existing models vary significantly in approach. We aimed to assess existing methodology and how it influences circulating sex-hormone levels in rodent models of TGM GAHT to provide recommendations of best practise. PubMed, Embase, and Scopus databases were systematically searched for studies that investigated GAHT in rodent models and were published from inception to the 1st of August 2024. Study characteristics and methodology were extracted and compared. Post-intervention circulating sex hormone concentrations were the primary outcome used to determine whether successful gender affirming hormone therapy had been achieved. Sixteen experimental rodent studies were included. Studies were performed on mice (n = 11) and rats (n = 5). Subcutaneous (SC) pellets and SC silastic implants were featured in some studies but weekly SC injections of testosterone enanthate was the preferred method. Sesame oil was the preferred solvent for injected testosterone formulations. Weekly doses of ~450 μg (mice) and ~420–900 μg (rats) consistently induced the testosterone levels of the male counterpart. Similarly, 10 mg of unesterified testosterone in a SC silastic implant in mice or 10 mg/100 g in rats were also successful methods. Most studies administered hormones for 6–8 weeks before performing post-treatment assessments. This review demonstrates that methods largely varied across studies and successfully identifies the effective methodological approaches that improve the reproducibility and accuracy of preclinical models. Representing an integral step forward to bridging gaps in preclinical transgender healthcare research.

Xenotransplantation, that is, the transplantation of cells, tissues, and organs between species, is a rapidly developing alternative to classical transplantology in human medicine. Since the first successful kidney transplant in 1954, transplant medicine has made enormous progress. Until today, there are numerous patients worldwide waiting for an organ to be transplanted, and the number is still increasing, whereas the number of available organs is decreasing. One promising solution to this critical issue is the breeding of genetically modified animals as potential donors, which has gained the attention of scientists over the past two decades. Recent advancements in xenotransplantation have led to successful transfers of genetically modified pig organs into human recipients. Particularly, pig kidneys have been transplanted into living humans, demonstrating normal postsurgical function. Additionally, pig lungs functioned for 9 days in a brain-dead individual without experiencing hyperacute rejection. Furthermore, the successful xenotransplantation of pig hearts into living persons, exhibiting life-sustaining graft function, underscores significant progress toward clinically viable xenotransplants. This review provides an updated overview of the animal species and models used in xenotransplantation, with particular emphasis on the potential of transgenic pigs as donors. It discusses the process involved in producing the aforementioned animals, including the methods used to modify their genome. Particular attention is paid to immunological and genetic barriers, as well as zoonotic risks, and the possibilities and limitations of this technology. Although xenotransplantation is still in its experimental stage, it may play a crucial role in saving patients' lives in the future.

Background: The investigation of ovarian development, dysfunction, and aging is essential for female reproductive health. Despite extensive research on the cellular functions of Brefeldin A (BFA) as an intracellular transport inhibitor, its specific effects and mechanisms on ovarian development/aging remain inadequately understood.

Methods: Mice and porcine oocytes/granulosa cells (GCs) were treated with BFA. Morphological and omics analyses (including Western blot, real-time polymerase chain reaction (RT-PCR), transcriptomics, and metabolomics) were conducted.

Results: In 3-week-old female mice, BFA treatment significantly suppressed oocyte maturation, induced apoptosis, and increased estradiol and LH levels. This treatment upregulated apoptosis-related genes while downregulating proliferation-associated genes. Additionally, BFA elevated senescence markers (p21 and p26) and decreased the activity of the longevity gene SIRT6. In porcine oocytes, BFA reduced the maturation rate and lowered mRNA levels of key maturation-related genes, LHX8 and GDF9. In porcine GCs, BFA increased apoptosis and upregulated genes such as Caspase-3, BAX, and P21, while downregulating genes associated with proliferation and longevity. Similar effects were observed in 12-month-old female mice, indicating consistency across age groups. Metabolomic analysis in these mice revealed that BFA primarily impacted pathways related to steroid biosynthesis, ovarian steroidogenesis, and estrogen signaling. Transcriptomic analysis in 12-month-old female mice further demonstrated that BFA disrupted ovarian function through multiple mechanisms, including modulation of the GnRH signaling pathway, activation of the FOXO pathway, and interference with meiosis-related gene expression.

Conclusion: Our findings are pivotal for advancing the understanding of ovarian aging, dysfunctions, and diseases, and ultimately facilitate addressing BFA's potential adverse effects on reproductive health/aging.

Background: Endoplasmic reticulum (ER) stress is an important factor in the development of numerous cardiovascular disorders; nevertheless, the association between ER stress and mitral regurgitation (MR) remains inadequately characterized. The molecular mechanism of pimobendan (PIMO) that contributes to the delay in congestive heart failure (CHF) in MR associated with apoptosis and fibrosis is still unclear. Our aim was to examine the impact of PIMO on ER stress, apoptosis, and fibrosis in a chronic MR rat model.

Methods: MR was surgically induced in 10 Sprague–Dawley rats, with 5 serving as sham operation controls. At 8 weeks postsurgery, the MR animals were randomly allocated into two groups: MR and MR + PIMO groups. PIMO was administered twice daily through oral gavage for 4 weeks, whereas the sham and MR groups were administered similar quantities of drinking water. Echocardiography was conducted before the delivery of PIMO as a baseline measure and at the end of the study. At the end of the investigation, hearts were procured for histopathological and ER stress evaluations.

Results: PIMO significantly maintained heart function and structural remodeling in the MR animals. PIMO significantly reduced MR-induced myocyte apoptosis (p = 0.044) and fibrosis (p = 0.002) by reducing the messenger RNA expression of genes associated with ER stress (GRP78 [glucose-regulated protein 78], ATF4 [activating transcription factor 4], and CHOP [C/ERP homologous protein]) compared to the MR group (p < 0.05, p < 0.01, and p < 0.001, respectively).

Conclusion: PIMO demonstrated cardioprotective benefits on heart function, myocyte apoptosis, and fibrosis by regulating ER stress in an MR-induced CHF rat model.

Background: Although widely used, the rat model remains poorly transferable to humans for peripheral nerve regeneration studies. The rabbit is a much better choice from an anatomical perspective. However, it remains little used due to the lack of available literature. The aim of this article is to demonstrate the feasibility and effectiveness of an electrophysiological protocol combined with a motor function assessment to analyze nerve repair.

Methods: Ten white New Zealand rabbits underwent a 4 cm transection of the fibular nerve. Autograft regeneration over 36 weeks was compared to non-repaired controls. The compound muscle action potential (CMAP) was recorded in the tibialis anterior and the extensor digitorum brevis. An electromyogram (EMG) was obtained after needle insertion and resting muscle activity recording. The electrophysiological results were compared to the toe spread index (TSI), which assesses the motor functional recovery promoted by fibular nerve regeneration.

Results: The autograft group regeneration starts between weeks 18 and 21 and normal EMG was observed around the 30th week. These electrophysiological results were compared to the well-defined toe spread reflex. This motor test showed a significant functional return of 59% at 36 weeks (p < 0.05). Rabbits regain nearly 80% of their muscle mass.

Conclusion: Nerve conduction allows detection of nerve regeneration of the muscle while electromyography indicates when muscle activity returns to normal. These studies are reliable and non-invasive techniques to evaluate fibular nerve regeneration in the rabbit's hindlimb. Nonetheless, it is necessary to have qualified personnel, since inter-manipulator variations have been observed.

Type 2 Diabetes (T2D) is a growing global health issue, often aggravated by excessive sugar intake. Chronic high-sucrose diets contribute to insulin resistance, oxidative stress, and pancreatic dysfunction, worsening metabolic health. Sodium-glucose co-transporter 2 (SGLT2) inhibitors, like empagliflozin, show potential in improving glycemic control and metabolic parameters, but their effects on pancreatic efficiency in sugar-induced T2D are not well understood. This study aimed to explore the effects of empagliflozin on metabolic and pancreatic protection in a high-sucrose diet-induced T2D model. Male Wistar rats were divided into four groups: normal, normal-treated, diabetic, and diabetic-treated (n = 8 per group). Diabetes was induced with a 35% sucrose solution for 8 weeks, followed by a low-dose streptozotocin (STZ) injection. Treated groups received empagliflozin (15 mg/kg/day) for the duration. Biochemical markers, including fasting blood sugar (FBS), lipid profile, insulin levels, and oxidative stress markers, were measured. Insulin resistance (HOMA-IR) and pancreatic function (HOMA-B) were assessed. Histological analysis of pancreatic tissues was performed. The high-sucrose diet increased FBS, insulin resistance, and oxidative stress, while decreasing pancreatic function and islet diameter. Empagliflozin treatment lowered FBS (p = 0.001), improved insulin sensitivity (p = 0.001), reduced triglycerides (p = 0.001), and LDL (p = 0.05). It also enhanced antioxidant enzymes, reduced lipid peroxidation (MDA, p = 0.001), and preserved pancreatic islet structure (p = 0.001). A high-sucrose diet negatively affects metabolic health and pancreatic function. Empagliflozin mitigates these effects by improving metabolism, reducing oxidative stress, and preserving pancreatic integrity, suggesting its potential as a therapeutic agent in diabetes related to excessive sugar consumption.

Background: Ketamine is a widely used anesthetic in animal research, but its use is strictly regulated in several countries, including Japan and China. As an alternative, the medetomidine-midazolam-butorphanol (MMB) combination is commonly used in Japan. However, medetomidine is a racemic mixture containing the inactive R-enantiomer, which may reduce anesthetic predictability and safety.

Objective: The aim of the study was to evaluate the efficacy and safety of a modified anesthetic combination (dMMB), in which dexmedetomidine replaces medetomidine, across three commonly used mouse strains (ICR, C57BL/6, BALB/c).

Methods: Male and female mice were administered either MMB or dMMB subcutaneously. Anesthetic depth, recovery profiles, heart rate, SpO₂, body temperature, ocular opacity, and blood glucose levels were assessed. Atipamezole was used to reverse anesthesia, and thermoregulatory recovery was monitored postinjection.

Results: dMMB produced similar anesthetic depth to MMB, with faster and more consistent recovery, particularly in males. Body temperature recovery was significantly enhanced in dMMB-treated B6 males. No significant differences in side effects (ocular opacity or blood glucose levels) were observed between protocols, though strain-specific glucose elevations were noted in dMMB-treated males.

Conclusion: dMMB is a safe, effective, and ketamine-free injectable anesthetic protocol, offering advantages in recovery and thermoregulation. It may be a valuable alternative in research settings where ketamine is restricted and medetomidine may become unavailable.